The understanding of protein function is greatly enhanced by the availability of three-dimensional structural information obtained by X-ray crystallography. Unfortunately the large, well-ordered three-dimensional crystals required for X-ray analyses have been difficult to produce for membrane proteins since they tend more naturally to form two-dimensional arrays. A further complicating factor in dealing with membrane proteins is the requirement for detergents to solubilize and stabilize the native structure. Although crystallization of membrane proteins is more of an art than a science as yet, it is clear that the structure and purity of the detergent are critical factors. In Phase l we will synthesize, purify and evaluate examples from a series of novel alkyl phosphocholine detergents as well as examples from two series of alkyl phosphoethanolamine detergents. These detergents will be tested for their ability to extract cytochromes and lactose permease in active form, and for crystallization of OmpC porin. In Phase II we will synthesize approximately ten to twenty more detergents in these three series and the utility of these detergents will be evaluated by their ability to extract in active form three different types of membrane proteins. The best candidates will be investigated for their ability to crystallize membrane proteins. PROPOSED COMMERCIAL APPLICATION: Available detergents are not satisfactory in many cases. A great need exists for new, pure structurally defined detergents for purifying and analyzing membrane proteins. Anatrace plans to market these new detergents to the research community via its established distribution routes.